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Indian Journal of Chemistry -Section A (IJC-A) >
IJC-A Vol.49A [2010] >
IJC-A Vol.49A(05-06) [May-June 2010] >
| Title: | Studies on interaction of ionic liquids with cyclodextrins in aqueous solution |
| Authors: | Li, Hong-Gang
Zhang, Qian
Zhao, Qiang
Liu, Min
Liu, Jie
Sun, De-Zhi |
| Keywords: | Ionic liquids
Cyclodextrins
Host-guest complexes
Microcalorimetry |
| Issue Date: | Jun-2010 |
| Publisher: | CSIR |
| Abstract: | Interactions between  -,  -,  -CDs and two ionic liquids, 1-butyl-3-methylimidazolium
tetrafluroborate ([bmim][BF4]) and 1-octyl-3-methylimidazolium
tetrafluroborate ([omim][BF4]), have been studied with titration
microcalorimetry and UV and NMR spectra at 298.15 K. The results are discussed
in terms of the hydrophobic interaction of CD molecular cavity with alkyl chain
of IL cation and the change in iceberg structure formed by water molecules
existing around the hydrophobic tail of the ionic liquids. The stoichiometry of
CDs with the two ionic liquids is 1:1 and 1:2 except that of -CD with [omim][BF4], which is only 1:1. The binding
process of -CD with both the ionic liquids is entropy
driven, while that of -CD and -CD with the ionic liquids is characterized by both enthalpy
favorable and entropy favorable processes.
The 1H NMR spectra reveal that chemical shift data of all protons in
-CD, -CD and
-CD molecules move to high field in the presence of ionic liquids.
UV absorbance for the CD-IL systems has been detected, which indicates that the
inclusion complex is formed through weak interaction. |
| Page(s): | 752-756 |
| Source: | IJC-A Vol.49A(05-06) [May-June 2010]
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